#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main() {
	int wait = 0;
	scanf("%d", &wait);
	int count = 0;
	while ((wait/12)>=1) {
		wait -= 12;
		count += 4;
	}
	count += 2;
	printf("%d", count);
	return 0;
}